The hydraulic jack has a shell, a big piston, a small piston, a wrench, an oil tank and other components. Principle of the hydraulic jack is a spanner to drive the small piston upward, oil in the oil through the oil pipe and a one-way valve is sucked into a small piston lower, wrench down the pressure driven piston down, tank and small in the lower part of the piston oil one-way valve, small in the lower part of the piston of oil through the internal circuit and a one-way valve is pressed into the lower part of the piston, because of the leverage effect is small in the lower part of the piston pressure is increased several times, the larger piston area is dozens of times more than the smaller piston area, manual pressure generation is packed into the large piston, Pascal's principle known size piston area ratio and pressure ratio on the contrary. As a result, hand force through a hydraulic jack wrench to the small piston on 10 times bigger (temporary by 15 times), a small piston to force of the large piston has increased 10 times (temporarily by 15 times), to the larger piston (the top of the car out of the movable part) times the strength =15X15=225 power, false if the hands with every 20 kilograms force, hydraulic jack can produce 20X225=4500 kg (4.5 tons) of power. Working principle of hydraulic jack is the case.
When the hydraulic jack is exhausted, a normally closed valve opened manually, oil on the weight of the car will be oil squeezed back to the tank. Hydraulic jack is a simple play heavy tools, applicable to bridge erection and factories, warehouses, docks, stack weights and vehicle tires and drag the replacement of the crawler can also be used for hull keel installation and welding work. Using this product, can reduce labor intensity, improve work efficiency.